• Journal of Microbiology and Biotechnology
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• v.11 no.6
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• pp.1099-1101
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• 2001

In an attempt to search for serotonin N-acetyltransferase (arylalkylamine N-acetyltransferasem, AA-NAT) inhibitors from microbial metabolites, we fecund the culture broth of Penicillium sp. 80722 which showed a strong inhibitory activity against AA-NNT. The active principle has been identified as citrinin hydrate through bioassay-guided fractionation of cultural broth, and structure elucidation derived by spectroscopic analyses. Citrinin hydrate inhibits AA-NAT with an $IC_50$ value of $173{\mu}M$ in a dose-dependent manner. Although citrinin hydrate was previously isolated as human rhinovirus 3C-protease inhibitor, this was recognized as the first AA-NAT inhibitor isolated from natural sources.

• Proceedings of the Materials Research Society of Korea Conference
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• 2011.05a
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• pp.7.1-7.1
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• 2011

Nanoporous templates have been widely used for the development of new functional nanostructured materials suitable for electronics, optics, magnetism, and energy storage materials. We have prepared nanoporous templates by using thin films of mixtures of polystyrene-block-poly (methyl methacrylate) (PS-b-PMMA) and PMMA homopolymers. These templates have cylindrical nanoholes spanning the entire thickness of the film. Some applications of nanoporous templates are introduced: a) anti-reflective coating, b) the preparation of conducting polymer nanowires of poly (pyrrole), poly (3,4-ethylenedioxy-thiopene) onto a glass coated with indium-tin-oxide, and c) the separation membranes for biomaterials. We found that when the pore fraction of nanoholes in the film was ~0.68, almost zero reflectance at a specific wavelength, which can be changed with film thickness, was achieved at visible wavelengths Furthermore, ultra high density array of conducting nanowires was successfully prepared onto various substrates including flexible polymer. Due to highly alignment of polymer chain along the nanowire direction, the conductivity was much increased. Furthermore, these nanoporous films were found to be very effective for the separation of human Rhinovirus type 14 (HRV 14), major pathogen of a common cold in humans, from the buffer solution. We also found that when the pore size was effectively controlled down to 6 nm, a single file diffusion was observed.

• Proceedings of the Polymer Society of Korea Conference
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• 2006.10a
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• pp.313-313
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• 2006

In this study, we describe a new double layered nanoporous membrane suitable for virus filtration. One layer is an 80 nm thick film having cylindrical pores with diameters of 15 nm and a narrow pore size distribution. This layer is prepared by using a thin film of the mixture of a block copolymer and a homopolymer, and mainly acts to separate viruses. The support layer (${\sim}150\;microns\;thick$) is a conventional micro-filtration membrane with a broad pore size distribution. This asymmetric membrane showed very high selectivity and flux for the separation of human rhinovirus type 14 (HRV 14) which has a diameter of ${\sim}30\;nm$ and is a major pathogen of the common cold in humans.

• Journal of Microbiology and Biotechnology
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• v.33 no.12
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• pp.1681-1691
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• 2023

Flavin mononucleotide-binding proteins or domains emit cyan-green fluorescence under aerobic and anaerobic conditions, but relatively low fluorescence and less thermostability limit their application as reporters. In this work, we incorporated the codon-optimized fluorescent protein from Chlamydomonas reinhardtii with two different linkers independently into the redox-responsive split intein construct, overexpressed the precursors in hyperoxic Escherichia coli SHuffle T7 strain, and cyclized the target proteins in vitro in the presence of the reducing agent. Compared with the purified linear protein, the cyclic protein with the short linker displayed enhanced fluorescence. In contrast, cyclized protein with incorporation of the long linker including the myc-tag and human rhinovirus 3C protease cleavable sequence emitted slightly increased fluorescence compared with the protein linearized with the protease cleavage. The cyclic protein with the short linker also exhibited increased thermal stability and exopeptidase resistance. Moreover, induction of the target proteins in an oxygen-deficient culture rendered fluorescent E. coli BL21 (DE3) cells brighter than those overexpressing the linear construct. Thus, the cyclic reporter can hopefully be used in certain thermophilic anaerobes.

• Pediatric Infection and Vaccine
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• v.21 no.2
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• pp.114-120
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• 2014

Purpose: The objective of this study was to assess and investigate the epidemiology of pertussis in infants under 6 months of age. Methods: A prospective study was conducted between October 1, 2011 and April 30, 2013 in CHA Bundang Medical Center, Seongnam, South Korea. Polymerase chain reaction (PCR) or culture was used to detect Bordetella pertussis in nasopharyngeal aspirates from case patients who were hospitalized for acute lower respiratory tract infection (LRTI). In addition, multiplex real-time PCR assays were also performed to detect 6 etiologic viruses, including adenovirus, human metapeumo-virus, influenza virus, parainfluenza virus, respiratory syncytial virus and rhinovirus. Results: Of the 79 enrolled case patients, whose median age was 2 months of age, the most common diagnoses uncovered in this study were acute bronchiolitis (60%) and pneumonia (28%). B. pertussis infection was found in 13 cases (16%), in which 7 (53%) was coinfected with respiratory syncytial virus and 1 (7%) with influenza A virus. Of the 13 patients with B. pertussis infection, 6 (46%) were not vaccinated with the diphtheria, tetanus toxoid, and acellular pertussis vaccine, while 6 (46%) received 1 dose, and 1 (8%) received 2 doses. Conclusion: B. pertussis infection was present in 16% of under 6 month-old infants, who were hospitalized for acute LRTI. Therefore, a nationwide epidemiological surveillance of pertussis, including institutions that cater to infants under 6 months of age is necessary and needed.

• Clinical and Experimental Pediatrics
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• v.61 no.6
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• pp.180-186
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• 2018

Purpose: Despite the availability of molecular methods, identification of the causative virus in children with acute respiratory infections (ARIs) has proven difficult as the same viruses are often detected in asymptomatic children. Methods: Multiplex reverse transcription polymerase chain reaction assays were performed to detect 15 common respiratory viruses in children under 15 years of age who were hospitalized with ARI between January 2013 and December 2015. Viral epidemiology and clinical profiles of single virus infections were evaluated. Results: Of 3,505 patients, viruses were identified in 2,424 (69.1%), with the assay revealing a single virus in 1,747 cases (49.8%). While major pathogens in single virus-positive cases differed according to age, human rhinovirus (hRV) was common in patients of all ages. Respiratory syncytial virus (RSV), influenza virus (IF), and human metapneumovirus (hMPV) were found to be seasonal pathogens, appearing from fall through winter and spring, whereas hRV and adenovirus (AdV) were detected in every season. Patients with ARIs caused by RSV and hRV were frequently afebrile and more commonly had wheezing compared with patients with other viral ARIs. Neutrophil-dominant inflammation was observed in ARIs caused by IF, AdV, and hRV, whereas lymphocyte-dominant inflammation was observed with RSV A, parainfluenza virus, and hMPV. Monocytosis was common with RSV and AdV, whereas eosinophilia was observed with hRV. Conclusion: In combination with viral identification, recognition of virus-specific clinical and laboratory patterns will expand our understanding of the epidemiology of viral ARIs and help us to establish more efficient therapeutic and preventive strategies.

• Journal of Life Science
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• v.27 no.3
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• pp.275-282
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• 2017

Adenovirus (ADV) and human bocavirus (hBoV) cause acute respiratory tract infections, and are often associated with increased rates of hospitalization and death, particularly in infants and young children. The aim of this study was to analyze the clinical features and molecular phylogeny of ADV and hBoV isolated in Busan, from January 2011 to November 2013. In total, 3,230 specimens (throat swabs) were collected from patients with influenza-like illnesses and acute respiratory tract infections. Multiplex real-time RT-PCR was performed to detect eight respiratory viru [rhinovirus, adenovirus, respiratory syncytial virus, human coronavirus, human metapneumovirus, human bocavirus, parainfluenza virus and influenza virus] and detected 1,485(46.0%) cases. Among 1,485 positive specimens, 257(8.0%) cases were ADV and 68(2.1%) cases of hBoV. A significant clinical feature of ADV is fever and headache whereas hBoV is wheezing. Serotypic distributions of isolated ADV and hBoV were analyzed by sequencing of hexon and VP1/VP2 gene, respectively. ADV was identified seven different serotypes(1~6, 8), revealing a high similarity among the isolates (>97%). The predominant types of ADV were type 1 in 2011, type 3 and 4 in 2012, type 3 in 2013, respectively. ADV type 3 was major causative type during outbreaks in 2013. All of the hBoV was identified as hBoV type 1.

• Pediatric Infection and Vaccine
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• v.18 no.1
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• pp.61-67
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• 2011

Purpose : This study was performed to investigate the epidemiologic characteristics of human bocavirus (HBoV)-associated lower respiratory tract infections (LRTIs) in children. Methods : Nasopharyngeal aspirate samples were obtained from 658 children who had been hospitalized for LRTIs in Seoul National University (SNU) Children's Hospital and SNU Bundang Hospital from March 2000 to September 2005. Multiplex RT-PCR was performed to detect 11 respiratory viruses including respiratory syncytial virus, adenovirus, rhinovirus, parainfluenza viruses 1 and 3, influenza viruses A and B, human metapneumovirus, HBoV, human coronavirus (HCoV) OC43/ 229E, and HCoV-NL63. Clinical data were reviewed retrospectively. Results : Overall, respiratory viruses were detected in 325 (49.4%) among 658 patients. HBoV was detected in 62 cases (9.4%) and was responsible for 19.1% of virus-positive cases. HBoV was prevalent among infants and young children aged from 3 months to 5 years with the mean age of 25.3 months. Co-detection of HBoV and other respiratory viruses was observed in 37.1% which is significantly higher than average co-detection rate (12.3%) among overall virus-positive cases (P=0.000). HBoV was identified mainly in late spring and early summer from May to July. Conclusion : This study describes epidemiologic features of HBoV in Korean children compared with those associated with other respiratory viruses. HBoV was prevalent among LRTIs in childhood, especially in late spring and early summer season in Korea.

• Pediatric Infection and Vaccine
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• v.17 no.1
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• pp.49-55
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• 2010

Purpose : The Purposes of this study are to identify the circulating etiologic viruses of acute lower respiratory tract infection in children and to understand the relation with clinical diagnosis. Methods : We obtained a total of 418 nasopharyngeal aspirates from children admitted for their acute lower respiratory tract infections at three tertiary hospitals in Seoul from September 2008 to March 2009. We performed multiplex RT-PCR to identify 14 etiologic viruses and analyzed their emerging patterns and clinical features. Results : Average age of patients was 16.4 months old and the ratio of male to female was 1.36. Viruses were detected in 56.2% of a total of 418 samples. Respiratory syncytial virus (35%) was the most frequently detected and followed by human rhinovirus (22%), human bocavirus, adenovirus, human metapneumovirus, parainfluenza virus, influenza virus and human coronavirus. Co-infection reached 21.9 % of positive patients. Conclusion : When we manage the patients with acute lower respiratory infectious diseases, we should remind the role of various viral pathogens, which might be circulating by seasons and by local areas.

• Pediatric Infection and Vaccine
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• v.30 no.2
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• pp.62-72
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• 2023

Purpose: A change is expected in the pattern of respiratory viruses including human coronavirus (HCoV) after the coronavirus disease 2019 (COVID-19) outbreak. Accordingly, identifying the distribution of respiratory viruses before the COVID-19 outbreak is necessary. Methods: We retrospectively analyzed the results of samples of nasal swabs collected from children under aged ≤18 years who were hospitalized at Myongji Hospital, Gyeonggi-do due to acute respiratory infections from 2017 to 2019. Viruses were detected by real-time reverse transcription polymerase chain reaction (RT-PCR). Results: Out of 3,557 total patients, 3,686 viruses were detected with RT-PCR including coinfections. Of the 3,557 patients, 2,797 (78.6%) were confirmed as PCR-positive. Adenovirus and human rhinovirus (hRV) were detected throughout the year, and human enterovirus was most detected during summer. Respiratory syncytial virus, influenza virus, and HCoV were prevalent in winter. In patients with croup, parainfluenza virus was most frequently detected, followed by hRV and HCoV. The PCR positive rate in summer and winter differed significantly. Conclusions: Respiratory virus patterns in northwestern Gyeonggi-do were not much different from previously reported data. The data reported herein regarding respiratory virus epidemiological information before the COVID-19 outbreak can be used for use in comparative studies of respiratory virus patterns after the COVID-19 outbreak.